Elevated storage tank



Nov. 3, 1953 B. BLACKBURN ELEVATED STORAGE TANK 2 Sheets-Sheet 1 Filed Oct. 25, 1950 WATER LEVEL BY 96 mg ATTORNEYS Nov. 3, 1953 B. BLACKBURN 2,657,819.

ELEVATED STORAGE TANK Filed Oct. 25, 1950 2 Sheets-Sheet 2 ,A mm

:73; 18 IN VENTOR ATTORNEYJ Patented Nov. 3, 1953 s r ELEVATED STORAGE TANK Bryan Blackburn, Newnan, Ga., assignor to R. D.

Cole Manufacturing 00., Newnan, Ga., a corporation of Georgia Application October 25, 1950, Serial No. 192,070

8 Claims. 1

This invention relates to elevated tanks or reservoirs for water or other liquids, particularly adapted for municipal water systems, industrial works, etc.

The general object of the invention is to provide a tank of the type described, characterized by unusual cleanness of structural design, combining maximum capacity with structural sturdiness, attractive appearance, facility of erection, and economy in the material required in its fabrication.

The invention is an improvement upon the tank disclosed in my Patent 1,947,515, granted February 20, 1934. Like the tank in said patent, it has the ornamental appearance of a spherical body resting in a saucer-shaped base. However, it differs radically from said patented tank from the standpoint of structure. In the patented construction the liquid is confined to the spherical portion of the tank, the base comprising nothing more than a circumferential series of radial brackets supporting the sphere, and covered with a metal skin as an appearance factor. With this arrangement it was necessary to provide a system of internal equatorial tensioners to enable the shell of the tank to carry the load. These had the form of upper and lower circumferential series of diagonal struts connected to the shell along the perimeter of its horizontal great circle and supported by the central vertical hub or access tube. These struts were at all times more or less submerged, and therefore subject to rapid corrosion, requiring periodic servicing. I

One of the principal objects of the present invention is to devise a tank of the general shape of that disclosed in said patent, in which the water carrying volume of the tank is extended to include the base which underlies the sphere, this structure involving joining the shell of the sphere with the shell of the base by a continuous circumferential reinforcement, which by virtue of its cross-sectional shape and the manner in which it is disposed, is adequate to absorb the load stresses to which the shell is subjected by the weight of the contained liquid.

Other objects of the invention will appear as the following description of a preferred and practical embodiment thereof proceeds.

In the drawings, throughout the several figures of which the same reference characters denote the same parts:

Figure 1 is a vertical section through an elevated tank embodying the invention, in part broken away, and parts being omitted;

Figure 2 is a view of the tank from above, one half being in plan and the other in section; V

Figure 3 is a section taken along the line 3-4 of Figure 1;

Figure 4 is a section taken along the line 44 of Figure 1;

Figure 5 is a fragmentary view in perspective, showing details of'construction associated with the system of radial tie rods shown in Figured;

Figure 6 is a section taken along the line 6--8 of Figure 1;

Figure '7 is a fragmentary view in vertical section, showing details of construction appertaining to the upper part of the tank; 1

Figure 8 is an enlarged cross-section of the annular beam shown in Figure 1. I

Referring now in detail to the several figures,

the tank which is designated as a whole by the reference numeral I, is mounted on top of a tubular tower 2, the upper part of which is shown in Figure 1.

The tank consists of a lower upwardly flaring part 3, having a shell 4 which is inwardly convex, and an upper spherical part 5, having a shell 6 which is outwardly convex. The shells 4 and 6 are fabricated in conventional manner of'metal plates, not individually delineated in the drawings, welded together, or otherwise secured. The tank has the dished bottom 1, circumferentially welded, as a matter of practical expediency, to the encompassing wall 8 of the tower just away from the joint between the top of the wall 8 and the adjacent end of the shell 4.

An open ended access tube 9 extends through,

the bottom I in watertight manner, communi eating with the interior of the tower, and it extends axially upward within the tank to a point 1 above the high water level, which level is determined by the height of the overflow pipe I 0, which also passes through the bottom 1. A coupling II for the supply pipe also opens through the bottom. Ladders l2 and 13, respectively,

extend along the inside and outside of the access.

tube 9, being secured by brackets I4, in spaced relation to the wall of said access tube. The adjacent ends of the spherical shell 6 and flaring shell 4 are joined through the intermediary of an annular beam l5 of Z-shaped crosssection, consisting of a web I 6 and upper and lower flanges I1 and la, the flanges being perpendicular to the web. In practice, this beam is made by welding together two angle bars, as shown in Figure 8. It will be readily understood that since the shell 4 curves inwardly it is in compression under the load of water in the tank,

while the spherical portion being outwardly convex, is under tension. Tanks of the present design are made oi! large size and to hold a great weight of water. A tank having a diameter of 28 feet may hold as much as 678,000 pounds of water. Although the shell 4 is the more heavily stressed, since it sustains the greatest depth of water. this is compensated by the shape of the shell 4 which, as stated, makes it a compression member under pressure from within. There is, however, an enormous pressure against the adjacent mouths of the shells 4 and 15, tending to expand them. In the 28 foot diameter tank, filled with water, the load amounts to 310 pounds for each linear inch throughout the circumference of these shells at their adjacent margins. In the absence of supporting means, the shells alone would be altogether inadequate to sustain this load.

The beam I5 is designed to be undeformable in any direction under any stresses to which it may be subjected. In a tank of the size indicated, the web it will be inches in depth and the flanges each 3 inches wide, the thickness of the material being inch. Such a beam cannot be twisted out of its diametrical plane, nor ovalized, nor distorted in any other way by the load or other stresses to which the tank may be subjected. The beam i5 is installed with the full depth of the web 16 in the direction in which the mouth of the shell 6 must expand in order for the shell to fail. Since the margin of the shell at said mouth must expand radially, the depth of the web it is in radial alignment with the spherical part of the tank, and converges toward the center of said spherical part, which center is marked with the character a, in Figure 1.

The shell 4 must expand outwardly in the same direction as the adjacent margin of the shell 6; therefore, the radial disposition of the web I6 is optimum for supporting the shell 4, as well as shell 6. The adjacent margins of the shells 4 and 6 are riveted to the flanges of the annular beam II.

The load bearing portion of the spherical part of the tank occupies a zone having an amplitude of about 45" on each side of its horizontal diametrical plane. The beam [5 is at the lower end 0! the zone. At the upper end, where there is very little internal pressure, the shell 6 is centralized with respect to the axis of the tank, and sustained by a system of radiating tie rods 19, connected between the shell 6 and the upper portion or the access tube 9. The details of this connection are as follows. One flange 20 of an annular angle member 2| is welded about the upper edge of the shell 8, projecting above it so as to form a rabbet 22. The other flange 23 projects inwardly all around. At regular intervals the flange 23 has the lugs 24 welded thereto and depending vertically therefrom. These lugs have perforations 25, receiving one end of the rods I! which are retained by nuts. The other ends pass through perforations 28 in the access tube, and are similarly retained. The tie rods and their connections are above water level.

By virtue of the beam IS on the one hand, and the tie rods 19 on the other, the tank I is adequately fortified against strains without the necessity of employing the submerged struts which characterize the tank disclosed in my hereinbefore mentioned patent.

The tank I is completed by an annular shoulder segment 21 of spherical curvature, which supports, in axial symmetry, a. cover plate 20, spaced therefrom by tubular separators 29, which surround rivets 30 that secure the cover plate to the shoulder segment, a narrow annular louver 3i being formed which permits the tank to freely breathe as the water becomes depleted and replenished, aerating the water and promoting drying of the exposed inner walls which minimizes corrosion. Back pressure also is relieved while the tank is being filled. The lower edge of the shoulder segment 21 fits within the rabbet 22 all around. and against the upper end of the shell 8. The joint may be welded or otherwise secured.

The cover plate is provided with a manhole 32 within reach of the ladder l2, closed by a ladder I. The cover plate also has an axially positioned pipe nipple 34, welded thereto, around which a painters hitch 35 is swivelly mounted. Said hitch has a hole 36 designed to be engaged by the scaffold rope, and may be oriented in any direction about the nipple 34. The pipe cap 21 keeps the hitch from coming on.

While I have in the above description disclosed what I believe to be a preferred and practical embodiment of the invention, it will be understood by those skilled in the art that the specific.

details of construction and the arrangement of parts are by way of example and not to be construed as limiting the scope of the invention.

What I claim as my invention is:

1. Storage tank for liquids comprising a shell constituting the direct bounding wall of a liquid containing chamber symmetrical with respect to a. vertical axis having a lower upwardly flared portion and an upper spherical portion, the adjacent ends of said portions being in spaced parallel planes the adjacent end of said spherical portion being above the adjacent end of said flared portion, and its diameter being less than the diameter of said flared portion as well as the great circle diameter of said spherical portion, and an annular beam of Z cross-section between the adjacent ends of said portions arranged with its web directed convergently substantially in the general direction of the center of said spherical portion. and having upper and lower flanges secured respectively circumferentially, to the adjacent end margins of said portions.

2. Storage tank for liquids as claimed in claim 1, including an access tube extending through the bottom of said lower portion substantially to the top of said upper portion, an annular angle bar secured circumferentially to said upper portion at the top having a flange extending inwardly, and a plurality of adjustable tie rods secured at intervals circumferentially between said flange and the wall of said access tube.

3. Storage tank for liquids as claimed in claim 1, including an access tube extending through the bottom of said lower portion and to the top of said upper portion coaxially of md shell, ladders extending along the inside and outside of said access tube to the top, secured to the wall of said tube, an annular angle bar having a flange secured circumferentially to said upper portion at the top projecting above the upper edge of said upper portion defining a rabbet therewith, a section having the shape of a spherical segment with its lower end fitted into said rabbet and secured and having spacers at intervals about its upper end, a cover section supported by said spacers providing ventilating louvers between said section and cover plate, the latter being provided with a manhole within reach of one of said ladders and a closure for said manhole.

4. Storage tank for liquids comprising a shell constituting the direct bounding wall of a liquid containing chamber having an upper portion defining a spherical zone extending depthwise on both sides of the horizontal great circle of said zone, and having a lower portion reversely curved with respect to said spherical zone, the adjacent ends of said portions being in spaced parallel planes, the adjacent end of said spherical portion being above the adjacent end of said flared portion and its diameter being less than the di ameter of said flared portion as well as the great circle diameter of said spherical portion, and an annular beam between said adjacent ends having a web and oppositely directed flanges from the side edges of said web, said flanges being circumferentially connected respectively to said adjacent ends, and said web being upwardly convergent in the general direction of the center of said spherical zone.

5. Storage tank for liquids as cla'uned in claim 4, said beam being formed by reversely arranged angle bars welded together at the contiguous edges of a flange of each.

6. Storage tank for liquids comprising a shell constituting the direct bounding wall of a liquid containing chamber having an upper portion defining a spherical zone extending depthwise on both sides of the horizontal great circle of said zone, terminating in horizontal planes, and an upwardly flared lower portion having a bottom, said lower portion being reversely curved with respect to said spherical zone, the adjacent ends of said portions being in spaced parallel planes, the adjacent end of said spherical portion being above the adjacent end of said flared portion and its diameter being less than the diameter of said flared portion as well as the great circle diameter of said spherical portion, said shell including an annular shoulder portion between said adjacent ends connected circumferentially to each and convergent in the general direction of the center of curvature of said upper portion, an access tube extending through the bottom of said lower portion substantially to the plane of the upper end of said upper portion, and a plurality of adjustable tie rods secured at intervals circumferentially between the upper edge of said upper portion and the wall of said access tube.

7. Storage tank for liquids comprising a shell constituting the direct bounding wall of a liquid containing chamber, symmetrical with respect to a vertical axis, having an upper spherical por" tion and a lower upwardly flared portion, the adjacent ends of said portions being in spaced parallel planes, the adjacent end of said spherical portion being above the adjacent end of said flared portion and its diameter being less than the diameter of said flared portion as well as the great circle diameter of said spherical portion, and a connecting conical portion of substantial width between the adjacent ends of said spherical and flared portions upwardly convergent in the general direction of the center of said spherical portion.

8. Storage tank for liquids comprising a shell constituting the direct bounding wall of a liquid containing chamber having an upper portion defining a spherical zone of uniform depth extending depthwise on both sides of the horizontal great circle of said upper portion, and having an upwardly flared lower portion, the adjacent ends of said portion being in spaced parallel planes the adjacent end of said spherical portion being above the adjacent end of said flared portion and its diameter being less than the diameter of said flared portion, and a conical connecting section of substantial width between said adjacent ends upwardly convergent in the general direction of the center of said spherical portion.

BRYAN BLACKBURN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 526,712 Johnston Oct. 2, 1894 783,148 Snow Feb. 21, 1905 1,163,804 Boley Dec. 14, 1915 1,165,011 Maddox Dec. 21, 1915 1,947,515 Blackburn Feb. 20, 1934 2,004,113 Horton June 11, 1935 2,295,514 Brinkman Sept. 8, 1942 2,417,053 Boardman Mar. 11, 1947 FOREIGN PATENTS Number Country Date 279,270 Germany Oct. 15, 1914 

